U.S. patent number 8,735,698 [Application Number 13/743,771] was granted by the patent office on 2014-05-27 for drive mechanism of lifting rail for musical instrument and musical instrument including the same.
This patent grant is currently assigned to Yamaha Corporation. The grantee listed for this patent is Yamaha Corporation. Invention is credited to Yuji Fujiwara, Yoshiya Matsuo, Yasuhiko Oba.
United States Patent |
8,735,698 |
Matsuo , et al. |
May 27, 2014 |
Drive mechanism of lifting rail for musical instrument and musical
instrument including the same
Abstract
A drive mechanism of a lifting rail for a musical instrument
including a lifting rail, the drive mechanism including: a
connection member connected to the lifting rail; and a
movement-force giving mechanism configured to move the lifting rail
via the connection member, wherein the lifting rail includes: a
hollow portion opening at one end; and a through-hole formed
through an upright wall portion of the lifting rail, wherein the
connection member includes: an insertion member having an
attachment hole corresponding to the through-hole; a fixing member
for connecting the lifting rail and the connection member; and a
contact portion configured to come into contact with the one end of
the lifting rail when the insertion member is inserted in the
hollow portion by a prescribed distance so as to prevent the
insertion member from being further inserted in the hollow portion,
thereby positioning the attachment hole relative to the
through-hole.
Inventors: |
Matsuo; Yoshiya (Hamamatsu,
JP), Oba; Yasuhiko (Hamamatsu, JP),
Fujiwara; Yuji (Hamamatsu, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Yamaha Corporation |
Hamamatsu |
N/A |
JP |
|
|
Assignee: |
Yamaha Corporation
(Hamamatsu-Shi, Shizuoka-Ken, JP)
|
Family
ID: |
48779065 |
Appl.
No.: |
13/743,771 |
Filed: |
January 17, 2013 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20130180376 A1 |
Jul 18, 2013 |
|
Foreign Application Priority Data
|
|
|
|
|
Jan 18, 2012 [JP] |
|
|
2012-008405 |
|
Current U.S.
Class: |
84/216 |
Current CPC
Class: |
G10C
3/26 (20130101); G10C 3/20 (20130101); G10C
3/22 (20130101); G10C 9/00 (20130101); Y10T
29/49826 (20150115) |
Current International
Class: |
G10C
3/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Horn; Robert W
Attorney, Agent or Firm: Dickstein Shapiro LLP
Claims
What is claimed is:
1. A drive mechanism of a lifting rail for a musical instrument
which comprises: dampers each configured to come into contact with
a sound generating member provided for a corresponding one of a
plurality of keys for generating a sound of one of a plurality of
pitches that are generated by the musical instrument, so as to
suppress a vibration of the sound generating member; damper levers
each connected to a corresponding one of the dampers directly or
indirectly for moving the damper away from the sound generating
member in accordance with depression of a corresponding one of the
plurality of keys; and a lifting rail having a bar-like
configuration and configured to operate all of the damper levers,
such that each of the dampers is spaced apart from the sound
generating member, the drive mechanism comprising: a connection
member to be connected to one end of the lifting rail; and a
movement-force giving mechanism configured to move the lifting rail
via the connection member in accordance with a signal to be
inputted thereto, wherein the lifting rail includes: a hollow
portion which is open at the one end of the lifting rail; and a
through-hole which is formed through an upright wall portion of the
lifting rail which stands in a vertical direction and which is one
of a plurality of wall portions of the lifting rail situated
between the hollow portion and an exterior of the lifting rail,
wherein the connection member includes: an insertion member in
which an attachment hole is formed at a position corresponding to
the through-hole and which is to be inserted in the hollow portion
of the lifting rail; and a fixing member configured to be inserted
into the through-hole and the attachment hole for connecting the
lifting rail and the connection member, and wherein the connection
member includes a contact portion configured to come into contact
with the one end of the lifting rail when the insertion member is
inserted in the hollow portion by a prescribed distance so as to
prevent the insertion member from being further inserted in the
hollow portion, thereby positioning the attachment hole relative to
the through-hole.
2. The drive mechanism of the lifting rail according to claim 1,
wherein the connection member is connected to the lifting rail in a
state in which the insertion member is inserted in the hollow
portion and is held in surface contact with an inner surface of the
upright wall portion of the lifting rail.
3. The drive mechanism of the lifting rail according to claim 1,
wherein the connection member includes: an external portion which
is formed integrally with an internal portion of the insertion
member and which is not inserted in the hollow portion, the
internal portion being to be inserted in the hollow portion of the
lifting rail, and wherein the contact portion is formed integrally
with the external portion.
4. The drive mechanism of the lifting rail according to claim 3,
wherein the external portion includes a contiguous surface which is
contiguous to a surface of the internal portion that is to be in
contact with an inner surface of the upright wall portion of the
lifting rail, and wherein the contact portion is formed along the
contiguous surface so as to extend outwardly with respect to at
least one horizontal wall portion among the plurality of wall
portions of the lifting rail, in a state in which the insertion
member is inserted in the hollow portion.
5. The drive mechanism of the lifting rail according to claim 1,
wherein the insertion member includes a rotation preventive portion
configured to be in contact with an inner surface of at least one
wall portion among the plurality of wall portions of the lifting
rail in a state in which the insertion member is inserted in the
hollow portion of the lifting rail, thereby preventing the
insertion member from rotating about an axis that is parallel to a
longitudinal direction of the lifting rail.
6. The drive mechanism of the lifting rail according to claim 1,
wherein the lifting rail includes at least one ridge portion
provided on at least one horizontal wall portion among the
plurality of wall portions of the lifting rail, so as to extend in
a longitudinal direction of the lifting rail.
7. The drive mechanism of the lifting rail according to claim 1,
further comprising at least one cushioning member which is an
elastic member and which is disposed between the lifting rail and
the connection member in the vertical direction, wherein a position
of the through-hole in the lifting rail and a position of the
attachment hole in the connection member are determined such that,
in a state in which a center position of the through-hole and a
center position of the attachment hole are aligned with each other
with the insertion member inserted in the hollow portion, a
dimension of a spacing in the vertical direction formed between the
lifting rail and the connection member at a location at which each
of the at least one cushioning member is located is smaller than a
dimension of each of the at least one cushioning member in the
vertical direction.
8. The drive mechanism of the lifting rail according to claim 7,
wherein the connection member includes an external portion which is
formed integrally with the insertion member and which is not
inserted in the hollow portion, and wherein the contact portion is
formed integrally with the external portion and is provided on one
side of the connection member in the vertical direction which is
opposite to the other side of the connection member in the vertical
direction on which each of the at least one cushioning member is
disposed.
9. The drive mechanism of the lifting rail according to claim 1,
wherein the connection member includes a first member as the
insertion member and a second member which is separate from the
first member and which is configured to receive a force from the
movement-force giving mechanism, and wherein the second member is
fixed to the first member and the lifting rail by the fixing
member.
10. The drive mechanism of the lifting rail according to claim 9,
wherein the insertion member and the contact portion are formed
integrally with the first member.
11. The drive mechanism of the lifting rail according to claim 9,
wherein the second member is connected to the lifting rail such
that a surface of a wall of the second member, in which an
attachment hole is formed so as to correspond to the through-hole,
is held in surface contact with an outer surface of the upright
wall portion of the lifting rail.
12. The drive mechanism of the lifting rail according to claim 9,
wherein the second member includes: a fixation portion to be fixed
to the lifting rail by the fixing member; and a force receive
portion formed integrally with the fixation portion and configured
to receive the force from the movement-force giving mechanism.
13. The drive mechanism of the lifting rail according to claim 1,
wherein the connection member is formed such that the insertion
member and a force receive portion are formed integrally with each
other, the force receive portion being configured not to be
inserted in the hollow portion and configured to receive a force
from the movement-force giving mechanism, and wherein the contact
portion is provided between the insertion member and the force
receive portion.
14. A musical instrument, comprising: the drive mechanism of the
lifting rail defined in claim 1; a performance-instruction-data
obtaining section configured to obtain performance instruction data
which instructs: generation of sounds constituting a music piece;
and attributes associated with the generation of the sounds, and a
signal generating section configured to generate signals to be
inputted to the movement-force giving mechanism, according to the
performance instruction data obtained by the
performance-instruction-data obtaining section.
15. A method of producing a drive mechanism of a lifting rail for a
musical instrument which comprises: dampers each configured to come
into contact with a sound generating member provided for a
corresponding one of a plurality of keys for generating a sound of
one of a plurality of pitches that are generated by the musical
instrument, so as to suppress a vibration of the sound generating
member; damper levers each connected to a corresponding one of the
dampers directly or indirectly for moving the damper away from the
sound generating member in accordance with depression of a
corresponding one of the plurality of keys; and a lifting rail
having a bar-like configuration and configured to operate all of
the damper levers, such that each of the dampers is spaced apart
from the sound generating member, wherein the drive mechanism
comprises: a connection member connected to one end of the lifting
rail; and a movement-force giving mechanism configured to move the
lifting rail via the connection member in accordance with signals
to be inputted thereto, the method comprising the steps of:
inserting an insertion member of the connection member into a
hollow portion of the lifting rail which is open at the one end of
the lifting rail; permitting a contact portion of the connection
member to come into contact with the one end of the lifting rail
when the insertion member is inserted in the hollow portion by a
prescribed distance; and fixing the connection member and the
lifting rail in a state in which the contact portion is in abutting
contact with the one end of the lifting rail.
Description
CROSS REFERENCE TO RELATED APPLICATION
The present application claims priority from Japanese Patent
Application No. 2012-008405 filed on Jan. 18, 2012, the disclosure
of which is herein incorporated by reference in its entirety
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a technique for driving dampers of
a musical instrument.
2. Description of Related Art
One example of a musical instrument equipped with damper mechanisms
is a piano. The following Patent Literature 1 discloses an
automatic playing piano as a piano in which dampers are driven by
actuators. The disclosed piano has a solenoid, and a loud lever is
in contact with a plunger of the solenoid. The loud lever is
supported by a fulcrum and rotates about the fulcrum when pushed by
the plunger, thereby pushing up a lifting push rod.
When the lifting push rod is pushed up, a lifting rail which is in
contact with an upper end of the lifting push rod is pushed up, so
that all of the dampers which are in pressing contact with
associated strings are forcibly separated therefrom. As a result,
sounds by the strings continue to be generated. This is because the
dampers are spaced apart from the strings in a time period during
which the lifting rail is pushed up, irrespective of whether keys
are depressed or not.
The loud lever is provided with a lever return spring which gives,
to the loud lever, a force in a direction opposite to a direction
in which the lifting push rod is pushed up. Accordingly, when the
solenoid is de-energized, the loud lever returns back to its
original position and the dampers come into pressing contact with
the strings. Patent Literature 1: JP-A-2002-14669
SUMMARY OF THE INVENTION
In a musical instrument equipped with the damper mechanisms, the
lifting rail needs to be pushed up for forcibly separating the
dampers all at once from the sound generating members such as the
strings.
In the piano disclosed in the Patent Literature 1, when the lifting
rail is pushed up by an actuator (solenoid), the force of the
actuator is transmitted to the lifting rail via the loud lever and
the lifting push rod.
If members other than the lifting rail are moved, e.g., the loud
lever and the lifting push rod are moved when the lifting rail is
pushed up, a drive force to be required for pushing up the lifting
rail is increased. Further, a noise which is generated when the
lifting rail is pushed up is also increased.
The present invention has been developed in the situations
described above. It is therefore a first object of the invention to
provide a drive mechanism of a lifting rail for a musical
instrument in which a required drive force is reduced and a noise
to be generated is reduced, when dampers are driven all at once
using an actuator. It is a second object of the invention to
provide a musical instrument including such a drive mechanism. It
is a third object of the invention to provide a method of producing
such a drive mechanism.
The first object indicated above may be achieved according to a
first aspect of the present invention, which provides a drive
mechanism of a lifting rail for a musical instrument which
comprises: dampers each configured to come into contact with a
sound generating member provided for a corresponding one of a
plurality of keys for generating a sound of one of a plurality of
pitches that are generated by the musical instrument, so as to
suppress a vibration of the sound generating member; damper levers
each connected to a corresponding one of the dampers directly or
indirectly for moving the damper away from the sound generating
member in accordance with depression of a corresponding one of the
plurality of keys; and a lifting rail having a bar-like
configuration and configured to operate all of the damper levers,
such that each of the dampers is spaced apart from the sound
generating member, the drive mechanism comprising:
a connection member to be connected to one end of the lifting rail;
and
a movement-force giving mechanism configured to move the lifting
rail via the connection member in accordance with a signal to be
inputted thereto,
wherein the lifting rail includes: a hollow portion which is open
at the one end of the lifting rail; and a through-hole which is
formed through an upright wall portion of the lifting rail which
stands in a vertical direction and which is one of a plurality of
wail portions of the lifting rail situated between the hollow
portion and an exterior of the lifting rail,
wherein the connection member includes: an insertion member in
which an attachment hole is formed at a position corresponding to
the through-hole and which is to be inserted in the hollow portion
of the lifting rail; and a fixing member configured to be inserted
into the through-hole and the attachment hole for connecting the
lifting rail and the connection member, and
wherein the connection member includes a contact portion configured
to come into contact with the one end of the lifting rail when the
insertion member is inserted in the hollow portion by a prescribed
distance so as to prevent the insertion member from being further
inserted in the hollow portion, thereby positioning the attachment
hole relative to the through-hole.
The second object indicated above may be achieved according to a
second aspect of the present invention, which provides a musical
instrument, comprising:
the drive mechanism of the lifting rail defined as described
above;
a performance-instruction-data obtaining section configured to
obtain performance instruction data which instructs: generation of
sounds constituting a music piece; and attributes associated with
the generation of the sounds, and
a signal generating section configured to generate signals to be
inputted to the movement-force giving mechanism, according to the
performance instruction data obtained by the
performance-instruction-data obtaining section.
The third object indicated above may be achieved according to a
third aspect of the present invention, which provides a method of
producing a drive mechanism of a lifting rail for a musical
instrument which comprises: dampers each configured to come into
contact with a sound generating member provided for a corresponding
one of a plurality of keys for generating a sound of one of a
plurality of pitches that are generated by the musical instrument,
so as to suppress a vibration of the sound generating member;
damper levers each connected to a corresponding one of the dampers
directly or indirectly for moving the damper away from the sound
generating member in accordance with depression of a corresponding
one of the plurality of keys; and a lifting rail having a bar-like
configuration and configured to operate all of the damper levers,
such that each of the dampers is spaced apart from the sound
generating member, wherein the drive mechanism comprises: a
connection member connected to one end of the lifting rail; and a
movement-force giving mechanism configured to move the lifting rail
via the connection member in accordance with signals to be inputted
thereto, the method comprising the steps of
inserting an insertion member of the connection member into a
hollow portion of the lifting rail which is open at the one end of
the lifting rail;
permitting a contact portion of the connection member to come into
contact with the one end of the lifting rail when the insertion
member is inserted in the hollow portion by a prescribed distance;
and
fixing the connection member and the lifting rail in a state in
which the contact portion is in abutting contact with the one end
of the lifting rail.
BRIEF DESCRIPTION OF DRAWINGS
The above and other objects, features, advantages and technical and
industrial significance of the present invention will be better
understood by reading the following detailed description of
embodiments of the invention, when considered in connection with
the accompanying drawings, in which:
FIG. 1 is an external view of an automatic playing piano according
to one embodiment of the present invention;
FIG. 2 is a schematic view showing an internal mechanical structure
of the automatic playing piano according to the embodiment of the
present invention;
FIG. 3 is a schematic view sowing a lifting rail, a connection
member, and a rail drive portion according to the embodiment of the
present invention;
FIG. 4 is a schematic view showing structures of the lilting rail
and the connection member according to the embodiment of the
present invention;
FIG. 5 is a schematic view showing a connected state of the lifting
rail and the connection member according to the embodiment of the
present invention;
FIG. 6 is a block diagram showing a structure of a controller
according to the embodiment of the present invention;
FIG. 7 is a block diagram showing a functional structure of the
controller according to the embodiment of the present
invention;
FIG. 8 is a schematic view showing a structure of a connection
member according to a modified embodiment of the present invention;
and
FIG. 9A is a schematic view showing a structure of a threaded hole
according to the embodiment of the present invention and FIG. 9B is
a schematic view showing a structure of a threaded hole according
to a modified embodiment of the present invention,
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 is an external view of an automatic playing piano 100
according to one embodiment of the present invention. In the
following explanation, a player's side of the piano 100 on which a
player is situated is referred to as a front side while an opposite
side to the player's side is referred to as a rear side, and a
right side and a left side as seen from the player are referred to
as a right side of the piano 100 and a left side of the piano 100,
respectively. Further, the lateral direction parallel to a
direction in which keys 1 are arranged is referred to as a
left-and-right direction, and a direction perpendicular to the
left-and-right direction and parallel to the horizontal direction
is referred to as a front-wad-rear direction, namely, a
longitudinal direction of each key is referred to as the
front-and-rear direction.
The automatic playing piano 100 has a plurality of keys 1 on the
front side and has, below the keys 1, a damper pedal 110, a
sostenuto pedal 111, and a soft pedal 112 which are disposed in
order from the right to the left. The automatic playing piano 100
further has an access portion 120 configured to read performance
instruction data in the MIDI format (Musical Instrument Digital
Interface) from a recording medium such as a DVD (Digital Versatile
Disk) or a CD (Compact Disk) in which the performance instruction
data is recorded. In addition, the automatic playing piano 100 has
an operation panel 130 beside a music stand. The operation panel
130 is a touch panel for accepting instructions from the player and
is configured to display various menu screens for operating the
automatic playing piano 100.
FIG. 2 is a schematic view showing an internal mechanical structure
of the automatic playing piano 100 as viewed from the left side.
The automatic playing piano 100 includes, for each of the plurality
of keys 1, at least one (from one to three) string 4 (each as a
sound generating member) configured to vibrate by being struck so
as to generate a sound of a prescribed pitch (hereinafter, at least
one (from one to three) string is simply referred to as "the
string" for the sake of brevity), a hammer 2 configured to strike
the string (sound generating member) 4, a hammer action mechanism 3
configured to move the hammer 2 in accordance with depression of
the associated key 1 so as to permit the hammer 2 to strike the
string (sound generating member) 4, a solenoid 50 configured to
drive the associated key 1 according to performance instruction
data so as to cause an action of the key 1 similar to an action
caused when the key 1 is actually depressed, and a key sensor 26
configured to measure a position of the key 1 in the vertical
direction.
The automatic playing piano 100 further has, for each of the keys 1
except for a predetermined number of the keys 1 in the treble
range, a damper 6 configured to be pushed and pressed by the
gravity onto the associated string (sound generating member) 4 so
as to suppress the vibration of the string (sound generating
member) 4 for sound silencing, and a damper mechanism 9 configured
to move the damper 6 according to depression of the associated key
1 so as to release the damper 6 from the string 4 (sound generating
member).
The automatic playing piano 100 further has: a plate-like key bed 5
on which the keys 1, etc., are placed; a box-like casing 51 which
is disposed in a through-hole formed through the key bed 5 in the
vertical direction and in which all of the solenoids 50 are
accommodated, the longitudinal direction of the casing 51
coinciding with the left-and-right direction; a cover 52 which
covers the lower surface of the through-hole in which the casing 51
is accommodated; a bar-like lifting rail 8 which is disposed below
the damper mechanisms 9 for pushing up all of the dampers 6
simultaneously and whose longitudinal direction coincides with the
left-and-right direction; and a lifting mechanism 11 configured to
push up the lifting rail 8 in accordance with depression of the
damper pedal 110 by the player.
Each damper mechanism 9 includes a damper lever 91 and a damper
wire 92 by which the damper 6 and the damper lever 91 are connected
in the vertical direction. The damper lever 91 is pivotally fixed,
at a vicinity of a rear-side end portion thereof by a pin 93. The
damper lever 91 is connected, at a vicinity of a front-side end
portion thereof, to the damper wire 92 via an adjuster to adjust
the length of the damper wire 92.
Below the front-side end portion of the damper lever 91, a
rear-side end portion of the associated key 1 is situated. In
accordance with depression of the key 1 by the player or the
solenoid 50, the rear-side end portion of the key 1 pushes up the
front-side end portion of the damper lever 91 from below. When the
damper lever 91 is pushed up, the damper 6 is pushed up via the
damper wire 92. As a result, the damper 6 is moved upward so as to
be separated away from the associated string (sound generating
member) 4.
When the key 1 is released from the depressed state and returns to
a prescribed position (position shown in FIG. 2) by gravity, the
damper mechanism 9 and the damper 6 also return to respective
prescribed positions (respective positions shown in FIG. 2). As a
result, the damper 6 comes into pressing contact with the string
(sound generating member) 4 for sound silencing.
The lifting mechanism 11 include& a pedal rod 116 disposed such
that the pedal rod 116 is connected to the damper pedal 110 so as
to extend upward from a rear-side end portion of the damper pedal
110 and such that an upper end portion of the pedal rod 116
contacts a front-side end portion of a loud lever 117 from below;
the loud lever 117 pivotally fixed, at the rear-side end portion
thereof, by a phi 113; a damper lifting rod 115 disposed such that
its lower end portion is connected to the loud lever 117 at a
middle position of the loud lever 17 in the front-and-rear
direction and such that its upper end portion contacts the lower
surface of the lifting rail 8 from below; and a spring 114 disposed
between the loud lever 117 and the cover 52 and configured to push
the loud lever 117 downward, i.e., in a clockwise direction in FIG.
2, such that the loud lever 117 pivots downward about the pin
113.
In a state in which the player does not depress a front-side end
portion of the damper pedal 110, the pedal rod 116, the loud lever
117, and the damper lifting rod 115 are being pushed downward by
the spring 114. In this state, the lifting rail 8 is located at a
prescribed lower position (position shown in FIG. 2) without being
pushed up by the damper lifting rod 115. Accordingly, the dampers 6
corresponding to the keys 1 which are not in the depressed state
press the associated strings 4 (sound generating members) from
above.
When the player depresses the front-side end portion of the damper
pedal 110 against the force of the spring 114, the pedal rod 116
connected to the rear-side end portion of the damper pedal 110 is
pushed up, whereby the loud lever 117, in which the upper end
portion of the pedal rod 116 is in abutting contact with the lower
surface of the loud lever 117, pivots about the pin 113 upward,
i.e., in a counterclockwise direction in FIG. 2. In association
with the pivotal movement of the loud lever 117, the damper lifting
rod 115 is pushed up, whereby the lifting rail 8, in which the
upper end portion of the damper lifting rod 115 is in abutting
contact with the lower surface of the lifting rail 8, is pushed up.
When the lifting rail 8 is pushed up, all of the damper levers 91
located above the lifting rail 8 pivot about the pins 93 upward,
i.e., in the counterclockwise direction in FIG. 2. In association
with the pivotal movements of the damper levers 91, the associated
dampers 6 are lifted up via the associated damper wires 92. As a
result, all of the dampers 6 are moved upward so as to be separated
away from the associated strings (sound generating members) 4.
When the player releases the damper pedal 110, the pedal rod 116,
the loud lever 117, and the damper lifting rod 115 return back to
the respective prescribed positions shown in FIG. 2 by the force of
the spring 114, and the lifting rail 8 returns back to the
prescribed position shown in FIG. 2 by gravity. As a result, all of
the damper mechanisms 9 and the dampers 6 corresponding to
non-depressed keys 1 return back to the respective prescribed
positions shown in FIG. 2 by gravity, so that the dampers 6 press
the associated strings (sound generating members) 4 to silence the
sounds.
As explained above, the automatic playing piano 100 has a mechanism
in which all of the dampers 6 are forcibly separated away from the
associated strings (sound generating members) 4 by pushing up the
lifting rail 8 via the lifting mechanism 11 when the player
depresses the damper pedal 110. In addition, the automatic playing
piano 100 has a mechanism in which all of the dampers 6 are
forcibly separated away from the associated strings (sound
generating members) 4 by directly pushing up the lifting rail 8
without using the lifting mechanism 11. The latter (additional)
mechanism will be hereinafter explained.
FIG. 3 is a schematic view as seen from the front side, showing a
right-side end portion of the lifting rail 8 of the automatic
playing piano 100, a connection member 53 connected to the lifting
rail 8 by screwing, a rail drive portion 54, as a movement-force
giving mechanism, configured to push up the lifting rail 8 via the
connection member 53 according to signals inputted thereto in
accordance with performance instruction data, and a rail sensor 55
configured to measure the position of the lifting rail 8 in the
vertical direction. The multiplicity of damper levers 91 which
correspond to the keys 1 are arranged in an orderly manner on the
upper surface of the lifting rail 8.
The rail drive portion 54 includes a solenoid 541 and a frame 542
to which the solenoid 541 is fixed.
The solenoid 541 includes a plunger 541a configured to move upward
in accordance with signals externally inputted as the electric
current and a spring 541b which pushes the plunger 541a upward such
that the plunger 541a is held in slight abutting contact with the
connection member 53.
In a state in which no electric current is supplied to the solenoid
541, the plunger 541a is located at a prescribed lower position by
being pushed downward by gravity of the lifting rail 8, etc. When
an electric current is supplied to the solenoid 541, the plunger
541a moves upward against the gravity owing to the Coulomb force
generated by a coil of the solenoid 541.
When the plunger 541a moves upward by the Coulomb force, the
plunger 541a pushes up the lifting rail 8 via the connection member
53 with which the upper end portion of the plunger 541a is held in
abutting contact. As a result, all of the dampers 6 are lifted up
via the respective damper mechanisms 9, so that the dampers 6 are
separated away from the associated strings (sound generating
members) 4.
The frame 542 is a strip-like metal member bent into a generally
inverted U-letter shape and is fixed to the key bed 5 by screwing,
for instance. There is formed, at a central position of an upper
wall of the frame 542, a circular through-hole having a
predetermined size through which the upper end portion of the
plunger 541a is movable in the vertical direction. The solenoid 541
is attached to a lower surface of the upper wall of the frame 542
by screwing, for instance.
The rail sensor 55 includes: a light transmission plate 551
attached to the connection member 53 so as to extend downward from
a prescribed position of the connection member 53; and a detecting
portion 552. The light transmission plate 551 is a plate-like
member formed of synthetic resin, for instance, and is processed
such that an amount of the light that passes therethrough varies
depending upon positions in the vertical direction. The detecting
portion 552 is a photo sensor having a light emission portion and a
light receive portion. The light emitted from the light emission
portion passes through the light transmission plate 551 and is
received by the light receive portion. The detecting portion 552 is
configured to output a signal in accordance with the amount of the
received light. In this arrangement, the signal outputted from the
detecting portion 552 indicates the position of the lifting rail 8
in the vertical direction.
FIG. 4 is a schematic view showing the structure of the connection
member 53 and the structure of the vicinity of the right-side end
portion of the lifting rail 8 to which the connection member 53 is
to be connected. FIG. 4 also shows a plurality of cushioning
members 56 which are elastic members and which are disposed between
the connection member 53 and the lifting rail 8 when the connection
member 53 is connected to the lifting rail 8.
As shown in FIG. 4, the lifting rail 8 is a hollow pipe-like member
having a rectangular cross-sectional shape. Each of a lower wall
portion 81 and an upper wall portion 82 of the lifting rail 8 is
provided with a plurality of ridge portions 83 each of which
protrudes inward from the corresponding wall portion 81, 82 so as
to extend along a longitudinal direction of the lifting rail 8. The
ridge portions 83 are for ensuring adequate strength of the lifting
rail 8.
In a front-side wall portion 84 of the lifting rail 8 located in
the vicinity of the right-side end portion of the same 8, three
through-holes 85 are formed through the thickness of the front-side
wall portion 84 in the horizontal direction. Where it is necessary
to distinguish the three through-holes 85 from one another, the
three through-holes 85 are respectively referred to as a
through-hole 85L, a through-hole 85C, and a through-hole 85R in
order from the left.
The connection member 53 includes: a first member 531 (as one
example of an insertion member) disposed such that a substantial
part of the first member 531 is inserted in a hollow portion 86 of
the lifting rail 8 and such that the first member 531 comes into
contact with an inner surface of the front-side wall, portion 84 of
the lifting rail 8; a second member 532 disposed such that the
second member 532 comes into contact with outer surfaces of the
respective front-side wall portion 84 and the lower wall portion 81
of the lifting rail 8; and three screws 533 (each as one example of
a fixing member) for connecting the connection member 53 to the
lifting rail 8. Here, the lifting rail 8 needs to be open at one
end thereof in the longitudinal direction, and the other end of the
lifting rail 8 in the longitudinal direction may be open or may be
closed.
Where it is necessary to distinguish the three screws 533 from one
another, the three screws 533 are respectively referred to as a
screw 533L, a screw 533C, and a screw 533R in order from the left
in accordance with respective positions when attached to the
connection members 53 and the lifting rail 8. Each of the screw
533L and the screw 533R is a countersunk head screw while the screw
5330 is a truss head screw.
The first member 531 has: a front-side wall portion 5311 which is
to come into contact with the inner surface of the front-side wall
portion 84 of the lifting rail 8; and a leg portion 5312 which
extends from a left-side end portion of the front-side wall portion
5311 toward the rear side so as to form an angle of 90.degree. with
respect to the front-side wall portion 5311. The leg portion 5312
is for supporting the first member 531 such that the first member
531 does not fall down. In other words, the leg portion 5312 is
held in contact with the lower wall portion 81 in a state in which
the first member 531 is inserted in the hollow portion 86 of the
lifting rail 8, thereby preventing the first member 531 from
rotating about an axis that is parallel the left-and-right
direction which coincides with the longitudinal direction of the
lifting rail 8. Thus, the leg portion 5312 functions as a rotation
preventive portion. The leg portion 5312 has a cutout for
permitting the ridge portions 83 formed on the lower wall portion
81 to pass therethrough.
The first member 531 further has a protruding portion 5313 (as one
example of a contact portion) which protrudes upward from a
right-side end portion of the front-side wall portion 5311. The
protruding portion 5313 is configured to come into contact with a
right-side end face of the lifting rail 8 when the first member 631
is inserted in the hollow portion 86 of the lifting rail 8 in the
longitudinal direction, thereby facilitating positioning of the
first member 531 in the left-and-right direction relative to the
lifting rail 8.
In the front-side wall portion 5311 of the first member 531, three
threaded holes 5314 (each as one example of an attachment hole) are
formed through the thickness of the front-side wall portion 5311 in
the horizontal direction. Into the three threaded holes 5314, the
three screws 533 indicated above are respectively screwed. The
inner circumferential surface of each threaded hole 5314 is formed
with thread grooves. The threaded grooves are formed at a pitch and
have a depth corresponding to thread ridges formed on the outer
circumferential surface of each of the screws 533. Where it is
necessary to distinguish the three threaded holes 5314 from one
another, the three threaded holes 5314 are respectively referred to
as a threaded hole 5314L, a threaded hole 5314C, and a threaded
hole 5314R in order from the left. In the first member 531, a
portion which is inserted in the hollow portion 86 of the lifting
rail 8 is an internal portion 5315, and a portion which is formed
integrally with the internal portion 5315 by one plate and which is
not inserted in the hollow portion 86 (i.e., a portion of the first
member 531 which is disposed outside the lifting rail 8) is an
external portion 5316. A surface 5317 of the internal portion 5315
of the front-side wall portion 5311 contacts the inner surface of
the front-side wall portion 84 of the lifting rail 8. A surface
5318 of the external portion 5316 of the front-side wall portion
5311 is formed on the same plane as the surface 5317 and is a
contiguous surface which is contiguous to the surface 5317. The
protruding portion 5313 is a part of the external portion 5316 and
extends on one side (the upper side) of the first member 531 which
is opposite to the other side (the lower side) of the first member
531 on which the cushioning members 56 are disposed. That is, the
protruding portion 5313 is formed integrally with the internal
portion 5315 disposed in the hollow portion 86 of the lifting rail
8, such that the protruding portion 5313 extends upwardly with
respect to the upper wall portion 82 of the lifting rail 8, in
other words, the top end of the protruding portion 5313 is located
at a height position higher than the upper wall portion 82, in a
state in which the first member 531 is inserted in the hollow
portion 86.
The second member 532 has: a front-side wall portion 5321 (as one
example of a fixation portion) which is to come into contact with
the outer surface of the front-side wall portion 84 of the lifting
rail 8; a lower wall portion 5322 which extends from a lower end
portion of the front-side wall portion 5321 toward the rear side so
as to form an angle of 90.degree. with respect to the front-side
wall portion 5321 and which is to come into contact with the outer
surface of the lower wall portion 81 of the lifting rail 8; a
right-side wall portion 5323 which extends upward from a right-side
end portion of the lower wall portion 5322 so as to form an angle
of 90.degree. with respect to the lower wall portion 5322 and which
is disposed so as to cover the right-side end face of the lifting
rail 8; and a force receive portion 5324 which extends rightward
integrally from an upper-side end face of the right-side wall
portion 5323 so as to form an angle of 90.degree. with respect to
the right-side wall portion 5323 and which is configured to receive
a force from the plunger 541a of the rail drive portion 54. It is
noted that the light transmission plate 551 is attached to the
lower surface of the force receive portion 5324, as shown in FIG.
3.
In the front-side wall portion 5321 of the second member 532, three
through-holes 5325 (each as one example of an attachment hole) are
formed through the thickness of the front-side wall portion 5321 in
the of horizontal direction. Into the three through-holes 5325, the
three screws 533 described above are respectively inserted. Where
it is necessary to distinguish the three through-holes 5325 from
one another, three through-holes 5325 are respectively referred to
as a through-hole 5325L, a through-hole 5325C, and a through-hole
5325R in order from the left. The through-hole 5325L and the
through-hole 5325R are subjected to countersinking processing. The
through-hole 5325C is contiguous to a cutout which is formed at the
upper end of the front-side wall portion 5321 so as to be
continuous to the through-hole 5325C. Accordingly, the through-hole
5325C is open upward.
A connection work for connecting the connection member 53 to the
lifting rail 8 is conducted as follows, for instance. Initially, a
worker places the cushioning members 56 at respective predetermined
positions on the upper surface of the lower wall portion 5322 of
the second member 532. On this occasion, the cushioning members 56
may be bonded to the lower wall portion 5322 by an adhesive or the
like to prevent the cushioning members 56 from being moved or
shifted from the predetermined positions in the connection
work.
Subsequently, the worker inserts the first member 531 into the
hollow portion 86 of the lifting rail 8. On this occasion, the
first member 531 is positioned relative to the lifting rail 8 such
that the front surface of the front-side wall portion 5311 of the
first member 531 comes into contact with the inner surface of the
front-side wall portion 84 of the lifting rail 8 and such that the
protruding portion 5313 of the first member 531 comes into contact
with the right-side end face of the lifting rail 8.
The leg portion 5312 extends from the front-side wall portion 5311
of the first member 531 toward the rear side and is configured to
come into contact with the lower wall portion 81 at a position at
which the leg portion 5312 is spaced apart from the front-side wall
portion 84 of the lifting rail 8 toward the rear side by a certain
distance. Accordingly, the first member 531 stands on its own while
being supported by the leg portion 5312, so that the first member
531 does not fall down in the lifting rail 8. Further, the front
part of the lower end portion of the first member 531 is sandwiched
by and between the front-side wall portion 84 and the most
frontward one of the ridge portions 83 formed on the inner surface
of the lower wall portion 81 of the lifting rail 8. Accordingly, in
the following screwing work of the screws 533, it is possible to
prevent the first member 531 from being pushed by the screws 533
and moved toward the rear side in the lifting rail 8.
When the first member 531 is disposed at the prescribed position in
the lifting rail 8 as described above, the through-holes 85 of the
lifting rail 8 are brought into communication with the
corresponding three threaded holes 5314 of the first member
531.
Thereafter, the worker inserts the screw 5330 into the through-hole
85C of the lifting rail 8 and the threaded hole 5314C communicating
with the through-hole 85C, and then screws the screw 533C into the
threaded hole 5314C. On this occasion, the worker suspends screwing
at a position at which a distance between the head of the screw
633C and the front-side wall portion 84 of the lifting rail 8 is
slightly larger than the thickness of the front-side wall portion
5321 of the second member 532.
Subsequently, the worker attaches the second member 532 on which
the cushioning members 56 have been placed or bonded, to the lower
surface of the lifting rail 8, such that the screw 5330 is fitted
into the through-hole 5325C of the second member 532, and
thereafter screws the screw 533C further into the through-hole
5325C so as to temporarily fix the second member 532 to the lifting
rail 8.
When the second member 532 is temporarily fixed to the lifting rail
8 by the screw 5330, the through-hole 5325L and the through-hole
5325R of the second member 532 are respectively brought into
communication with the through-hole 85L and the through-hole 85R of
the lifting rail 8; and the threaded hole 5314L and the threaded
hole 5314R of the first member 531 which are respectively in
communication with the through-hole 85L and the through-hole
85R.
Next, the worker inserts the screw 533L into the through-hole
5325L, the through-hole 85L, and the threaded hole 5314L which are
held in communication with one another, and tightly screws the
screw 533L into the threaded hole 5314L. Similarly, the worker
inserts the screw 533R into the through-hole 5325R, the
through-hole 85R, and the threaded hole 5314R which are held in
communication with one another, and tightly screws the screw 533R
into the threaded hole 5314R. Thereafter, the worker tightly screws
the screw 5330 which has been temporarily fixed, into the threaded
hole 5314C.
When the screw 533L is tightly screwed into the threaded hole
5314L, the center of the through-hole 5325L and the centers of the
through-hole 85L and the threaded hole 5314L align with each other.
Similarly, when the screw 533R is tightly screwed into the threaded
hole 5314R, the center of the through-hole 5325R and the centers of
the through-hole 85R and the threaded hole 5314R align with each
other. In the present embodiment, the positions of the
through-holes and the threaded holes are determined such that the
dimension of a spacing (distance) between the lower wall portion
5322 of the second member 532 and the lower wall portion 81 of the
lifting rail 8 is equal to 1.2 mm, for instance, in a state in
which the center of the through-hole 5325L and the centers of the
through-hole 85L and the threaded hole 5314L align with each other
and the center of the through-hole 5325R and the centers of the
through-hole 85R and the threaded hole 5314R align with each other
as described above. On the other hand, the thickness of each of the
cushioning members 56 disposed between the lower wall portion 5322
of the second member 532 and the lower wall portion 81 of the
lifting rail 8 is equal to 1.4 mm, for instance. In a state in
which the screw 533L and the screw 533R are tightly screwed into
the threaded hole 5314L and the threaded hole 5314R, respectively,
the inner surface of the front-side wall portion 84 of the lifting
rail 8 and the surface 5317 of the first member 531 are held in
surface contact with each other. Similarly, in that state, the
outer surface of the front-side wall portion 84 of the lifting rail
8 is held in surface contact with the inner surface of the
front-side wall portion 5321 of the second member 532.
As described above, in a state in which the second member 532 is
attached to the lifting rail 8, the dimension of the spacing
(distance) between the lifting rail 8 and the second member 532 is
adjusted so as to be smaller than the original thickness of each
cushioning member 56, whereby the so-called rattling does not occur
between the lifting rail 8 and the second member 532 owing to the
restoring force of the compressed cushioning members 56, ensuring
secure fixation of the second member 532 to the lifting rail 8.
Thus, the connection work for connecting the connection member 53
to the lifting rail 8 is completed. FIG. 5 is a schematic view
showing the lifting rail 8, the connection member 53, and the
cushioning member 56 after completion of the connection work, as
viewed from the left side.
There will be next explained an electric structure of the automatic
playing piano 100. The automatic playing piano 100 has a controller
10 configured to control the above-indicated solenoids 50 and
solenoid 541 for automatic performance.
FIG. 6 is a block diagram showing the structure of the controller
10. The controller 10 includes a CPU (Central Processing Unit) 102,
a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, A/D
converting sections 105, PWM-signal generating sections 106, an A/D
converting section 107, and a PWM-signal generating section 108.
The controller 10 further includes the access portion 120 and the
operation panel 130 described above. Those functional sections are
connected to one another via a bus 101.
The A/D converting section 105 and the PWM-signal generating
section 106 are provided for each of all keys 1 and serve as
functional sections for controlling the position of the associated
key 1. On the other hand, since the A/D converting section 107 and
the PWM-signal generating section 108 are functional sections for
controlling the position of the lifting rail 8, only one A/D
converting section 105 and only one PWM-signal generating section
106 are provided.
The CPU 102 is configured to read performance instruction data from
a recording medium inserted in the access portion 120 according to
the control program stored in the ROM 103 utilizing the RAM 104 as
a work area and to drivingly control the solenoids 50 and the
solenoid 541 according to the read performance instruction data,
thereby executing automatic performance. The CPU 102 functions as a
performance-instruction-data obtaining section.
FIG. 7 is a block diagram showing the functional structure of the
controller 10 for automatic performance. The CPU 102 functions as a
motion controller 1000a and a motion controller 1000b by executing
processing according to the control program.
The motion controller 1000a controls movements of the keys 1. The
motion controller 1000a is configured to generate trajectory data
that indicates which keys 1 should be located at which positions at
what timing, on the basis of note-on data and note-off data
contained in the performance instruction data of the MIDI format
obtained from the recording medium.
On the other hand, each A/D converting section 105 is configured to
convert an analog signal outputted from the associated key sensor
26 into a digital signal and to output the digital signal after
conversion, to the motion controller 1000a.
The motion controller 1000a is configured to execute a servo
control for each of the keys 1, such that a position at which the
key 1 should be currently located and which is indicated by the
generated trajectory data coincides with a current position of the
key 1 indicated by the signal inputted thereto from the All)
converting section 105. The motion controller 1000a outputs, to the
PWM-signal generating section 106a, a drive signal indicative of a
drive force in accordance with a speed to be required for the
movement of the key 1.
The PWM-signal generating section 106 is configured to convert the
drive signal inputted thereto from the motion controller 1000a into
a PWM signal of a PWM (Pulse Width Modulation) format and to output
the PWM signal to the solenoid 50 of the associated key 1. The
solenoid 50 displaces the corresponding plunger according to the
PWM signal inputted thereto from the PWM-signal generating section
106. As a result, the key 1 is depressed by the solenoid 50
according to the performance instruction data.
The motion controller 1000b controls the movement of the lifting
rail 8. The motion controller 1000b is configured to generate
trajectory data that indicates at which position the lifting rail 8
should be located at what timing, on the basis of control change
data indicative of a position of the damper pedal contained in the
performance instruction data of the MIDI format obtained from the
recording medium.
On the other hand, the A/D converting section 107 is configured to
convert an analog signal outputted from the rail sensor 55 into a
digital signal and to output the digital signal after conversion,
to the motion controller 1000b.
The motion controller 1000b is configured to execute a servo
control, such that a position at which the lifting rail 8 is
currently located and which is indicated by the generated
trajectory data coincides with a current position of the lifting
rail 8 indicated by the signal inputted thereto from the A/D
converting section 107 coincide with each other. The motion
controller 1000b outputs, to the PWM-signal generating section 108,
a drive signal indicative of a drive force in accordance with a
speed to be required for the movement of the lifting rail 8. The
motion controller 1000b and the PWM-signal generating section 108
function as a signal generating section.
The PWM-signal generating section 108 is configured to convert the
drive signal inputted thereto from the motion controller 1000b into
a PWM signal and to output the PWM signal to the solenoid 541. The
solenoid 541 displaces the plunger 541a according to the PWM signal
inputted thereto from the PWM-signal generating section 108. As a
result, the lifting rail 8 is pushed up by the solenoid 541
according to the performance instruction data.
In the manner described above, the keys 1 are driven by the
solenoids 50 and the lifting rail 8 is driven by the solenoid 541
under the control of the controller 10, whereby automatic
performance involving the loud effect is realized.
According to the automatic playing piano 100 described above, in
automatic performance, the lifting rail 8 is directly driven by the
solenoid 541 via the connection member 53 connected directly to the
lifting rail 8, for forcibly releasing all of the dampers 6
simultaneously from the associated strings 4. Consequently, as
compared with an arrangement in which the lifting rail 8 is
indirectly driven via the lifting mechanism 11, for instance, it is
possible to reduce the drive force required for driving the lifting
rail 8 and to reduce the noise generated by driving of the lifting
rail 8.
In the automatic playing piano 100, the front-side wall portion 84
of the lifting rail 8 is sandwiched by and between the first member
531 and the second member 532 as described above. Therefore, even
where the lifting rail 8 is formed of a material with relatively
low hardness such as aluminum, sufficiently strong connection
between the connection member 53 and the lifting rail 8 is ensured
without a fear of damaging the lifting rail 8 when the connection
member 53 is attached to the lifting rail 8.
For ensuring such connection, it is required to perform the
screwing work with respect to the first member 531 inserted in the
hollow portion 86 of the lifting rail 8. In general, in an instance
where an inner member to be inserted in a pipe-like member is
formed with a threaded hole and a screw is fitted into the threaded
hole from an outer side of the pipe-like member, it is difficult to
perform positioning of the threaded hole of the inner member
relative to a through-hole formed in the pipe-like member. Further,
when the screw is pushed into the threaded hole of the inner
member, there may be a risk that the inner member having the
threaded hole moves in the pipe-like member and sometimes falls
down. Hence, the screw fastening work involves difficulty.
In contrast, according to the connection member 53 employed in the
automatic playing piano 100, the positioning of the first member
531 relative to the lifting rail 8 is easy owing to the protruding
portion 5313, and there is not risk that the first member 531 falls
down in the lifting rail 8, owing to the leg portion 5312.
Therefore, the present automatic playing piano 100 do not suffer
from the problems described above. Further, the leg portion 5312
has the cutout in which the ridge portions 83 are accommodated,
namely, the leg portion 5312 straddles the ridge portions 83.
Accordingly, even where the first member 531 receives, from the
screw 533C, a force in a direction from the front side to the rear
side when the first member 531 is temporarily fixed to the lifting
rail 8 by the screw 5330, the ridge portions 83 can receive the
force. Therefore, the first member 531 is prevented from moving
toward the rear side in the hollow portion 86 of the lifting rail
8. Accordingly, it is possible to enhance the working efficiency in
connecting the connection member 53 to the lifting rail 8.
Further, in the present automatic playing piano 100, the dimension
of the spacing (distance) formed between the lifting rail 8 and the
connection member 53 in a state in which the connection member 53
is connected to the lifting rail 8 is adjusted to be smaller than
the thickness of each of the cushioning members 56 disposed in the
spacing. Accordingly, more secure connection of the connection
member 53 with respect to the lifting rail 8 is ensured.
Moreover, since the protruding portion 5313 is formed integrally
with the internal portion 5315 of the first member 531, it is
possible to enhance the positioning accuracy of the connection
member 53 relative to the lifting rail 8, as compared with an
arrangement in which the protruding portion 5313 is formed
separately or independently from the internal portion 5315.
Further, since the external portion 5316 including the protruding
portion 5313 is formed on the same plane as the internal portion
5315, the position of the protruding portion 5313 relative to the
internal portion 5315 is more accurate and it is possible to ensure
a higher degree of positioning accuracy of the connection member 53
relative to the lifting rail 8, as compared with an arrangement in
which the protruding portion 5313 is formed by bending work. In
addition, since the protruding portion 5313 is provided so as to
protrude on the upper side of the lifting rail 8 opposite to the
lower side of the same 8 on which the cushioning members 56 are
disposed, the protruding portion 5313 can be made so as to have a
desired size that does not depend on the size of the spacing
between the lifting rail 8 and the connection member 53. Further,
since the first member 531 and the second member 532 are separate
from and independent of each other, the first member 531 can be
easily inserted into the lifting rail 8.
Modified Embodiment
While one embodiment of the present invention has been described
above, it is to be understood that the present invention is not
limited to the details of the illustrated embodiment, but may be
embodied with various other changes and modifications without
departing from the scope of the invention defined in the attached
claims. Hereinafter, modified embodiments will be explained.
In the illustrated embodiment, the connection member 53 is
constituted by the first member 531 and the second member 532 which
are separate members. The connection member 53 may be constituted
by the first member 531 and the second member 532 which are
connected to each other.
In the illustrated embodiment, there is employed a structure in
which the lifting rail 8 is sandwiched by the first member 531 and
the second member 532, such that the first member 531 disposed
inside the lifting rail 8 and the second member 532 disposed
outside the lifting rail 8 are fastened using the screws 533. There
may be employed other structure in which the lifting rail 8 is
sandwiched by the heads of the screws and an insertion member which
is a portion of the connection member inserted in the hollow
portion 86 of the lifting rail 8, without providing, in the
connection member, a member disposed outside the front-side wall
portion 84 of the lifting rail 8, as described below.
FIG. 8 is a view schematically showing a structure of a connection
member 57 as one example of the connection member having the
structure indicated above. The connection member 57 includes: an
insertion member 571 (as one example of an internal portion) which
has an inverted U-letter shape and which is a portion of the
connection member 57 to be inserted in the hollow portion 86 of the
lifting rail 8; a right-side wall portion 572 (as one example of an
external portion) which is a portion of the connection member 57
not to be inserted in the hollow portion 86 of the lifting rail 8
and which extends upward from a right-side upper end face of the
insertion member 571; a force receive portion 573 which is a
portion of the connection member 57 not to be inserted in the
hollow portion 86 of the lifting rail 8 and which extends from
rightward from a right-side upper end face of the right-side wall
portion 572; and screws 575L, 575C, 575R (each as one example of a
fixing member) which are to be screwed into threaded holes 574L,
574, 574R (each as one example of an attachment hole) which are
formed in the front-side wall portion of the insertion member 571
in this order from the left side. Each of the screws 575L, 575C,
575R is a truss head screw. The insertion member 571, the
right-side wall portion 572, and the force receive portion 573 are
formed integrally with each other by one plate. The right-side wall
portion 572 is formed between the insertion member 571 and the
force receive portion 573.
The shape and the size of the insertion member 571 are adjusted
such that the insertion member 571 fits to the inside of the
lifting rail 8. The insertion member 571 is inserted in the hollow
portion 86 of the lifting rail 8. A rear-side wall portion 576,
which is a portion of the insertion member 571 and which is formed
integrally with a front-side wall portion and an upper wall portion
of the insertion member 571, comes into contact with the lower wall
portion 81 of the lifting rail 8 on the front side of the rear-side
wall portion of the lifting rail 8. In a state in which the
insertion member 571 is inserted in the lifting rail 8, a left-side
end face of the right-side wall portion 572 (as one example of a
contact portion) contacts the right-side end face of the lifting
rail 8, whereby the connection member 57 is positioned relative to
the lifting rail 8 in the left-and-right direction. When the
connection member 57 is thus positioned relative to the lifting
rail 8, the through-hole 85L, the through-hole 85C, and the
through-hole 85R of the lifting rail 8 are respectively brought
into communication with the threaded hole 574L, the threaded hole
574C, and the threaded hole 574R of the connection member 57.
Subsequently, the worker inserts the screws 575 into the
through-holes 85 and the threaded holes 574 that are held in
communication with one another, and the screws 575 are then screwed
into and fastened with respect to the threaded holes 574.
In the modified embodiment shown in FIG. 8, no cushioning members
are used in connecting the connection member 57 to the lifting rail
8. The cushioning members may be used in the modified embodiment.
In this instance, the cushioning members may be disposed between
the upper surface of the insertion member 571 and the lower surface
of the upper wail portion 82 of the lifting rail 8, for instance.
Where the cushioning members are thus disposed, it is preferable to
adjust the positions of the through-holes 85 and the threaded holes
574 such that there is formed, between the insertion member 571 and
the upper wall portion 82 of the lifting rail 8, a spacing whose
dimension in the vertical direction is smaller than the original
thickness of the cushioning members, as in the illustrated
embodiment.
As explained above, the connection member 57 also ensures easy
connection work with respect to the lifting rail 8.
The connection member 57 is constituted such that the insertion
member 571 to be inserted in the lifting rail 8, the right-side
wall portion 572, and the force receive portion 573 are integral
with each other, whereby processing of the connection member 57 is
facilitated. In a state in which the connection member 57 is
inserted in the lifting rail 8, the rear-side wall portion 576 of
the insertion member 571 is held in contact with the lower wall
portion 81 of the lifting rail 8, whereby the connection member 57
is prevented from falling down in the lifting rail 8. In this
respect, the rear-side wall portion 576 functions as a rotation
preventive portion.
In the illustrated embodiment, the thread grooves of each threaded
hole 5314 are formed on the inner circumferential surface of the
threaded hole 5314. As long as each screw 533 can be fastened with
respect to the first member 531 by screwing, the shape of the
threaded hole 5314 and the position at which the thread grooves are
formed are not particularly limited.
Referring to FIGS. 9A and 9B, there will be explained a modified
structure of the threaded hole 5314. FIG. 9A schematically shows
the shape of the threaded hole 5314 and the position of the thread
grooves of the threaded hole 5314 in the illustrated embodiment.
FIG. 9B schematically shows the shape of the threaded hole 5314 and
the position of the thread grooves of the threaded hole 5314
according to the modified structure. The threaded hole 5314 shown
in FIG. 913 is constituted by: a nut attached by welding on the
rear surface of the front-side wall portion 5311 of the first
member 531; and a through-hole formed through the thickness of the
front-side wall portion 5311 so as to communicate with a threaded
hole of the nut. According to the threaded hole 5314 shown in FIG.
9B, the screws 533 can be fastened by screwing with respect to the
first member 531 more securely, as compared with the threaded hole
5314 shown in FIG. 9A.
In the illustrated embodiment, the solenoid type actuator is
employed as the actuator for driving the lifting rail 8. There may
be employed actuators of other types such as a hydraulic actuator
and a motor type actuator.
The solenoid 541 employed in the illustrated embodiment is one
example. As the actuator, there may be employed other solenoids
such as a solenoid not equipped with the spring 541b.
In the illustrated embodiment, the connection member 53 is
connected to the right-side end portion of the lifting rail 8. In
addition or instead, the connection member 53 may be connected to
the left-side end portion of the lifting rail 8. In this instance,
the rail drive portion 54 and the rail sensor 55 are disposed also
on the left-side end portion of the lifting rail 8.
In the illustrated embodiment, the lifting rail 8 is driven under
the servo control. For driving the lifting rail 8, there may be
employed an arrangement in which the servo control is not
executed,
In the illustrated embodiment, as the performance instruction data,
the data of the MIDI format is used. The performance instruction
data of other format may be used.
In the illustrated embodiment, the screws are used for fixing the
connection member 53 or the connection member 57 to the lifting
rail. The fixation of the connection member to the lifting rail may
be otherwise conducted. For instance, in place of the threaded
holes 5314 or the threaded holes 574, there may be formed
attachment holes in which no thread grooves are formed. Rivets,
each as a fixing member, may be inserted into the through-holes and
the attachment holes for fixation. Bolts, each as a fixing member,
and nuts may be used for fixation.
In the illustrated embodiment, the piano has been explained as the
musical instrument equipped with the damper mechanisms, by way of
example. The present invention is applicable to various other
musical instruments, such as celesta and glockenspiel, equipped
with the damper mechanisms for silencing sounds generated by sound
generating members configured to vibrate by being struck. In this
instance, the movements of the dampers may be stored as performance
data and the dampers may be driven based on the performance data,
as in the piano of the illustrated embodiment.
* * * * *